Figure 17.15 VSG genes may be created by
duplicative transfer from an internal or telomeric basic copy into an
expression site, or by activating a telomeric copy that is already present
at a potential expression site.

Figure 17.18 The expression-linked copy of a VSG
gene contains barren regions on either side of the transposed region,
which extends from ~1000 bp upstream of the VSG coding region to a site
near the 3¢F terminus of the
mRNA.